Electronic paper driving method and device and display equipment

Abstract

The invention discloses an electronic paper driving method and device and display equipment. The electronic paper driving method comprises the steps that multiple source data rows are generated; generating a plurality of zero padding data rows corresponding to the plurality of source data rows one by one according to the source data rows; performing global continuous data flow on the plurality of source data rows and the plurality of zero-fill data rows, wherein the global continuous data flow is configured with preset time sequence parameters so that the source data rows and the zero-fill data rows of the same row are sequentially output in a single-row grid period; and generating a driving time sequence signal, starting the gate line according to the driving time sequence signal, and synchronously controlling the source driving circuit to write data twice in a single-row gate period so as to drive display. According to the electronic paper driving method and device and the display equipment, the source data row and the zero-padding data row are generated, the two sets of data are sequentially output in the single-row grid electrode period, the pixel electrode is forced to discharge to the zero potential, the voltage difference caused by TFT electric leakage is eliminated, and the display uniformity is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to an electronic paper driving method, device and display equipment. Background Art

[0002] Figure 1 It is a conventional cholesteric LCD single-pixel driving architecture, mainly composed of a source line, a gate line, a common terminal, a TFT transistor and a pixel electrode, wherein the source line is used to send data to the drain of the TFT transistor, and the gate line controls the gate of the TFT transistor to control the TFT on or off. The pixel electrode is connected to the source of the TFT transistor, and is used to receive and store data signals and form an electric field with the common terminal electrode to control the deflection of the liquid crystal. Figure 2 and Figure 3 The voltage and timing characteristics of the conventional drive architecture are shown respectively, among which, Figure 2 It is the DC common voltage and source voltage driving timing of conventional reflective LCD / ink screen. Figure 3 This is a schematic diagram of the data writing timing of a conventional cholesteric LCD, that is, the gate waveform output by the gate drive circuit is scanned line by line, and each line is turned on, and the source will write the corresponding data (positive voltage / negative voltage / GND). However, in the conventional timing, after the voltage data is written, before the next frame is written, this voltage will cause the charged voltage to drop (usually 2-3V) due to TFT leakage. Due to the fluctuation of the TFT transistor process, the uniformity of the TFT transistor characteristics of the entire control panel also varies. This difference will cause the voltage drop between TFT transistors to be different, so the maximum difference of TFT transistors on a whole screen may reach more than 3V. This will cause the cholesteric display screen to have uniformity and image quality problems when entering the FC state or the grayscale display between the P state and the FC state. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention provides an electronic paper driving method, device and display equipment.

[0004] In a first aspect, the present invention provides an electronic paper driving method, comprising: generating a plurality of source data rows, wherein each source data row contains a valid voltage sequence equal to the number of panel columns; Generate multiple zero-filled data rows corresponding to multiple source data rows one by one according to the source data rows; The multiple source data rows and the multiple zero-filled data rows are globally continuous data streams, and the global continuous data streams are configured with preset timing parameters so that the source data rows and the zero-filled data rows of the same row are sequentially output within a single row gate cycle; Generate a driving timing signal, turn on the gate line according to the driving timing signal and synchronously control the source driving circuit to write data twice within a single row gate cycle to drive the display.

[0005] Preferably, generating multiple rows of zero-padded data rows corresponding one-to-one to multiple rows of source data rows according to source data rows is specifically as follows: a zero value sequence is added to the end of the effective voltage sequence of the source data row to generate a zero-padded data row, wherein the zero value sequence is equal to the number of source data rows and columns; the zero value sequence of the zero-padded data row is used to force the pixel electrode to discharge to zero potential within a single row gate cycle.

[0006] Preferably, forming the multiple source data rows and the multiple zero-filled data rows into a global continuous data stream specifically comprises: arranging the multiple source data rows and the multiple zero-filled data rows alternately in rows and then splicing them into the global continuous data stream.

[0007] Preferably, generating multiple source data rows specifically includes: Acquire the image to be displayed, analyze the pixel-level target optical state of the image to be displayed, and convert the target optical state of each pixel into a corresponding driving voltage value according to the voltage-optical characteristic mapping relationship of the cholesteric liquid crystal; The row data formed by arranging the driving voltage values ​​according to the number of columns of the display panel is a plurality of source data rows.

[0008] Preferably, converting the target optical state of each pixel into a corresponding driving voltage value specifically includes: Receiving a digital image signal of an image to be displayed; Mapping the grayscale value of the image pixel to a target optical state of the cholesteric liquid crystal, wherein the target optical state includes a planar state, a focal conic state, and an intermediate grayscale state; According to the voltage-optical characteristic lookup table of the cholesteric liquid crystal, the target optical state is converted into a corresponding driving voltage value.

[0009] Preferably, the two data writing steps specifically include: In the first writing operation, a source data row voltage is applied to the source line to drive the liquid crystal molecules to switch to the target optical state; In the second writing operation, a zero-filled data row voltage is applied to the source line to return the pixel electrode to zero potential.

[0010] Preferably, the single row gate period in the preset timing parameters is specifically ; In the same single-row gate cycle, the source data row output period occupies 40%-55% of the cycle; the zero-filled data row output period occupies 45%-60% of the cycle.

[0011] Preferably, the method further comprises: After all rows are driven, the display panel is kept in a field-free state, and the image display is maintained by utilizing the bistable characteristics of the cholesteric liquid crystal.

[0012] In a second aspect, the present invention provides an electronic paper driving device, comprising: A data generation module, used for generating multiple source data rows; A data processing module, used for generating, according to source data rows, multiple rows of zero-filled data corresponding one-to-one to multiple rows of source data rows; A timing generation module is used to convert multiple source data rows and multiple zero-filled data rows into a global continuous data stream, and the global continuous data stream is configured with preset timing parameters so that the source data rows and zero-filled data rows of the same row are output in sequence within a single row gate cycle; The driving module is used to generate a driving timing signal, turn on the gate line according to the driving timing signal and synchronously control the source driving circuit to write data twice within a single row gate cycle to drive the display.

[0013] In a third aspect, the present invention provides an electronic paper display device, comprising the electronic paper driving device and a cholesteric liquid crystal display panel; the device is applied to an electronic reader, an electronic tag or a low-power information display terminal.

[0014] In the present invention, the proposed electronic paper driving method, device and display device generate source data rows and zero-filled data rows, and output two sets of data in sequence within a single-row gate cycle, forcing the pixel electrode to discharge to zero potential, eliminating the voltage difference caused by TFT transistor leakage, and significantly improving display uniformity. At the same time, the logic control core optimizes the timing parameters, integrates data writing and discharge operations into a single-row cycle, and reduces the number of gate switches. This solution is suitable for cholesteric liquid crystal display devices, has the characteristics of low power consumption and high refresh efficiency, and can be widely used in scenarios such as electronic readers and electronic tags. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of a conventional cholesteric LCD single pixel driving architecture; Figure 2 This is a schematic diagram of the DC common voltage and source voltage driving timing of a conventional reflective LCD / ink screen; Figure 3 This is a schematic diagram of the scanning timing structure of a conventional reflective LCD / ink screen; Figure 4 A schematic diagram of a scanning timing structure of an electronic paper driving method proposed by the present invention; Figure 5 A schematic diagram of the structure of an implementation process of an electronic paper driving method proposed by the present invention; Figure 6 A schematic diagram of the working process structure of an electronic paper driving method proposed in the present invention. DETAILED DESCRIPTION

[0016] Reference Figure 4-6 The present invention provides an electronic paper driving method, comprising the following steps: S1. Generate multiple source data rows.

[0017] In this embodiment, multiple source data rows are generated, specifically including: Acquire the image to be displayed, analyze the pixel-level target optical state of the image to be displayed, and convert the target optical state of each pixel into a corresponding driving voltage value according to the voltage-optical characteristic mapping relationship of the cholesteric liquid crystal; The row data formed by arranging the driving voltage values ​​according to the number of columns of the display panel is a plurality of source data rows.

[0018] In this embodiment, the target optical state of each pixel is converted into a corresponding driving voltage value, specifically including: receiving a digital image signal of an image to be displayed; mapping the grayscale value of the image pixel to a target optical state of a cholesteric liquid crystal, the target optical state including a planar state, a focal-conic state and an intermediate grayscale state; and converting the target optical state into a corresponding driving voltage value according to a voltage-optical characteristic lookup table of the cholesteric liquid crystal.

[0019] Specifically, each source data row contains a sequence of valid voltages equal to the number of panel columns.

[0020] Specifically, the target optical state is mapped to a corresponding driving voltage value, for example, the planar state P state corresponds to +50V, the focal conic state FC state corresponds to +15V, and the grayscale state is allocated 1-30V as needed.

[0021] S2. Generate multiple zero-filled data rows corresponding to multiple source data rows one by one according to the source data rows.

[0022] In this embodiment, multiple rows of zero-padded data rows corresponding to multiple rows of source data rows are generated according to source data rows in a one-to-one manner as follows: a zero value sequence is added to the end of the effective voltage sequence of the source data row to generate a zero-padded data row, wherein the zero value sequence is equal to the number of source data rows and columns; the zero value sequence of the zero-padded data row is used to force the pixel electrode to discharge to zero potential within a single row gate cycle.

[0023] In this embodiment, the zero value sequence of the zero-filled data row is used to force the pixel electrode to discharge to zero potential within a single row gate period.

[0024] Specifically, a zero value sequence of the same length is added to the end of each row of valid voltage data. For example, if a row of valid data is [+15V, +10V, +5V], the zero-filled data is [0V, 0V, 0V].

[0025] S3, forming a global continuous data stream of multiple source data rows and multiple zero-filled data rows, and configuring the global continuous data stream with preset timing parameters so that source data rows and zero-filled data rows of the same row are outputted sequentially within a single row gate cycle.

[0026] In this embodiment, forming a global continuous data stream of multiple source data rows and multiple zero-filled data rows is specifically as follows: arranging multiple source data rows and multiple zero-filled data rows alternately in rows and then splicing them into a global continuous data stream.

[0027] In this embodiment, the single row gate period in the preset timing parameters is specifically: .

[0028] Specifically, in the same single-row gate cycle, the source data row output period occupies 40%-55% of the cycle; the zero-filled data row output period occupies 45%-60% of the cycle.

[0029] Furthermore, the source data and the zero-filled data are alternately arranged through the FPGA logic control core to generate a driving timing signal. For example, in each row of gate-on cycle, source data rows are outputted in sequence → zero-filled data rows.

[0030] S4, generating a driving timing signal, turning on the gate line according to the driving timing signal and synchronously controlling the source driving circuit to write data twice within a single row gate cycle to drive the display.

[0031] In this embodiment, the two data writing operations specifically include: in the first writing operation, a source data row voltage is applied to the source line to drive the liquid crystal molecules to switch to the target optical state; in the second writing operation, a zero-filling data row voltage is applied to the source line to return the pixel electrode to zero potential.

[0032] In this embodiment, it also includes: After all rows are driven, the display panel is kept in a field-free state, and the image display is maintained by utilizing the bistable characteristics of the cholesteric liquid crystal.

[0033] It should be noted that the LCD display screen includes a display panel, which includes a gate driving circuit, a plurality of gate lines arranged in rows, a plurality of pixel electrodes, a plurality of source lines arranged in columns, and a source driving circuit. The gate driving circuit drives and controls the plurality of gate lines arranged in rows, and the source driving circuit drives and controls the plurality of source lines arranged in columns.

[0034] Specifically, Figure 4As shown, in order to solve the voltage leakage difference caused by TFT difference, the driving timing will write data N-1 frames and the last frame N frames of the displayed image (discharge frame, discharge the charged voltage to GND) when the gate of the same row is opened, and write the two frames of data of the conventional timing in the same frame. That is, when the gate of a row is opened, the source writes two values, the voltage and GND corresponding to the current pixel. In this way, after each row of gates is opened and closed, all pixel electrodes return to GND after completing the voltage operation on LC. This timing allows the pixel to no longer need to maintain high voltage data to the next frame, so there is no voltage difference problem caused by leakage, which can improve display uniformity and image quality. And because there is no need to maintain voltage between frames, the time for LC to apply the electric field can be reduced, and the polarization problem of LC can also be improved. In addition, the gate is opened once to write data twice, and only one gate rise and fall is experienced, which is compared to opening twice (2 frames) and experiencing two gate rises and falls, resulting in 3~5 frames to be fully charged or completely discharged, which can reduce the overall refresh time.

[0035] Specifically, Figure 5 As shown, FPGA can be used as the logic control core to replace the conventional Tcon for image processing, and all the data after the valid source data in all rows are filled with 0 data to generate 2 sets of source data, and the driving timing is realized by increasing the gate single-row scanning time by 1 times in coordination with the timing.

[0036] Reference Figure 4-6 The present invention provides an electronic paper driving device, comprising: A data generation module, used for generating multiple source data rows; A data processing module, used for generating, according to source data rows, multiple rows of zero-filled data corresponding one-to-one to multiple rows of source data rows; A timing generation module is used to convert multiple source data rows and multiple zero-filled data rows into a global continuous data stream, and the global continuous data stream is configured with preset timing parameters so that the source data rows and zero-filled data rows of the same row are output in sequence within a single row gate cycle; The driving module is used to generate a driving timing signal, turn on the gate line according to the driving timing signal and synchronously control the source driving circuit to write data twice within a single row gate cycle to drive the display.

[0037] Reference Figure 4-6 The present invention provides an electronic paper display device, comprising the electronic paper driving device mentioned above, and a cholesteric liquid crystal display panel.

[0038] In this embodiment, the device is applied to an electronic reader, an electronic tag, or a low-power information display terminal.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An electronic paper driving method, characterized in that: include: generating a plurality of source data rows, wherein each source data row contains a valid voltage sequence equal to the number of panel columns; Generate multiple zero-filled data rows corresponding to multiple source data rows one by one according to the source data rows; The multiple source data rows and the multiple zero-filled data rows are globally continuous data streams, and the global continuous data streams are configured with preset timing parameters so that the source data rows and the zero-filled data rows of the same row are sequentially output within a single row gate cycle; Generate a driving timing signal, turn on the gate line according to the driving timing signal and synchronously control the source driving circuit to write data twice within a single row gate cycle to drive the display.

2. The electronic paper driving method according to claim 1, characterized in that: Generating multiple rows of zero-padded data rows corresponding to multiple rows of source data rows one by one according to source data rows is specifically as follows: a zero-value sequence is added to the end of the effective voltage sequence of the source data row to generate a zero-padded data row, wherein the zero-value sequence is equal to the number of source data rows and columns; the zero-value sequence of the zero-padded data row is used to force the pixel electrode to discharge to zero potential within a single row gate period.

3. The electronic paper driving method according to claim 1, characterized in that: The global continuous data stream of multiple source data rows and multiple zero-filled data rows is specifically: the multiple source data rows and multiple zero-filled data rows are alternately arranged row by row and then spliced ​​into the global continuous data stream.

4. The electronic paper driving method according to claim 1, characterized in that: The generating of multiple source data rows specifically includes: Acquire the image to be displayed, analyze the pixel-level target optical state of the image to be displayed, and convert the target optical state of each pixel into a corresponding driving voltage value according to the voltage-optical characteristic mapping relationship of the cholesteric liquid crystal; The row data formed by arranging the driving voltage values ​​according to the number of columns of the display panel is a plurality of source data rows.

5. The electronic paper driving method according to claim 4, characterized in that: The converting the target optical state of each pixel into a corresponding driving voltage value specifically includes: Receiving a digital image signal of an image to be displayed; Mapping the grayscale value of the image pixel to a target optical state of the cholesteric liquid crystal, wherein the target optical state includes a planar state, a focal conic state, and an intermediate grayscale state; According to the voltage-optical characteristic lookup table of the cholesteric liquid crystal, the target optical state is converted into a corresponding driving voltage value.

6. The electronic paper driving method according to claim 1, characterized in that: The two data writings specifically include: In the first writing operation, a source data row voltage is applied to the source line to drive the liquid crystal molecules to switch to the target optical state; In the second writing operation, a zero-filled data row voltage is applied to the source line to return the pixel electrode to zero potential.

7. The electronic paper driving method according to claim 1, characterized in that: The single row gate period in the preset timing parameters is specifically: ; In the same single-row gate cycle, the source data row output period occupies 40%-55% of the cycle; the zero-filled data row output period occupies 45%-60% of the cycle.

8. The electronic paper driving method according to claim 1, characterized in that: The method further comprises: After all rows are driven, the display panel is kept in a field-free state, and the image display is maintained by utilizing the bistable characteristics of the cholesteric liquid crystal.

9. An electronic paper driving device, characterized in that: include: A data generation module, used for generating multiple source data rows; A data processing module, used for generating, according to source data rows, multiple rows of zero-filled data corresponding one-to-one to multiple rows of source data rows; A timing generation module is used to convert multiple source data rows and multiple zero-filled data rows into a global continuous data stream, and the global continuous data stream is configured with preset timing parameters so that the source data rows and zero-filled data rows of the same row are output in sequence within a single row gate cycle; The driving module is used to generate a driving timing signal, turn on the gate line according to the driving timing signal and synchronously control the source driving circuit to write data twice within a single row gate cycle to drive the display.

10. An electronic paper display device, characterized in that: It comprises the electronic paper driving device as claimed in claim 9, and a cholesteric liquid crystal display panel; the device is applied to an electronic reader, an electronic tag or a low-power information display terminal.

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